Shares of American footwear firm Crocs have plunged nearly 30% after it warned of a drop in sales as US shoppers rein in their spending.

The rubber clog maker says it expects revenue for the three months to the end of August to fall by about 10% compared with last year, saying that some shoppers are no longer visiting Crocs stores.

"We see the US consumer behaving cautiously around discretionary spending," said the firm's chief executive Andrew Rees.

The company's share price is now at its lowest level for nearly three years after suffering the worst single-day drop in almost 15 years.

Crocs warned of a "concerning" second half of the year, due to the high cost of living and the potential impact of US President Donald Trump's trade policies.

Its chief financial officer, Susan Healy, said Crocs would take a $40m (£29.8m) hit for the remainder of 2025 due to tariffs.

"I think we can over the medium-term mitigate the impact of tariffs. That will come from cost savings in our supply chain," said Mr Rees.

The footwear maker also warned that it has seen "ample evidence" that a portion of its customer base is now "super cautious" with their spending.

"They're not purchasing, they're not even going to the stores, and we see traffic down," Mr Rees said during a call with investors and journalists.

Crocs said it will continue to pull back on discounting its products, cautioning that this could have a further impact on sales.

Ahead of next year's football World Cup in the US, Mexico and Canada and the 2028 Los Angeles Olympics, Mr Rees said consumers are "migrating back towards athletic" products.

His comments came after Crocs reported second quarter revenue of $1.1bn, a 3% rise compared to the same period last year.

The company also owns casual footwear brand HEYDUDE, following a $2.5bn takeover in late 2021.